Paper-pulp digester



(NoModel.) l Y E. H. LAPP,

PAPER PULP DPGPSTPR.

N0. 305,740. l Patented' Sept. 30, 1884. F15 l l f f 'FI-5 3 'EUNTTnrr STaTns PATENT @Trice EUGENE H. CLAPP, OF BOSTON, MASSACHUSETTS.

PAPER-PULP DIGESTER.

'.,LLCIFICATION forming part of Letters Patent No. 305,740, dated September 30, 1884.

Application filed August 1S, 1854.. (No model.)

To /LZ/ whom, it' 'ln/fm concern:

Be it known that l, EUGENE H. Cnilrr, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Pulp- Digesters, of which the following description, in connection with the accompanying drawings, isa specication, like letters on the drawings representing like parts.

My invention relates to an apparatus for digesting Wood pulp; and it consists in details of construction hereinafter specified.y

The apparatus consists, essentially, of a tight case or receiver for containing the pulp material to be treated, the said receiver having Within it the usual pipes or appliances for passing steam through the mass of pulp material, in order to properly heat the saine, and also a pump for maintaining a circulation of liquid charged with the proper chemicals through the material in the receiver. A discharge-opening is provided for the pulp material, controlled by a valve seating on a ridge or annular projection surrounding the dischargeopening and constituting the valveseat, the face ofthe valve being provided with a packing-ring of lead or equivalent soft metal where it engages the seat, thus insuring a tight joint unaffected by Wear or chemical. action. rEhe valve is constructed, as hereinafterdescribed, so as to enable itt-o be easily removed, and provided Wit-l1 a new packing-ring when one is Worn out, thus enabling the v'alve to be kept in proper condition with but little cost or loss of time.

Figure 1 is a side elevation of an apparatus for digesting pulp material embodying thisinvention; Fig. 2, a longitudinal section of the valve through which the pulp material is discharged, on alarger scale; and Fig. 3, a transverse section yof the, said valve on line .e frz, Fig. 2.

The main tank or receiver a, provided with a removable cover or bonnet, b, to receive the pulp material and liquids and chemicals by which it is to be treated, may beof usual construction, it containing a perforated false bottoni, (shown indotted lines at 0,) which sup# ports the pulp material and permits the liquid.

to percolatc through it, the said liquid eollecting in the bottom of the tank and being drawn therefrom through apipe, d, and forced by a suitable pump or forcing apparatus (shown at e, Fig. 1,) through a pipe, f, back inte the receiver u, Where it is delivered upon the top of the pulp material contained therein, again passing through the said material, which is heated by a suitable coil of pipes (shown as entering) leaving the tank at g IL, the said pipe being supplied .vitli steam from a suitable generator. Then the pulp material has been sufficiently acted upon by the chemicals and is thoroughly digested, it is withdrawn from the lower end ofthe tank a through a discharge-passage, fi, controlled by a valve, it, (shown on a larger scale in Figs. 2 and 3,)the said valve consisting, essentially, of a case or shell, 7s', provided With a flange, k2, adapted to be bolted or otherwise fastened to the discharge-opening of the tanl; a. The said case la is provided with an annular projection or raised valve-seat, 75', (shown as tl-shaped in cross-seetion,) which receives the valve proper 7s, operated by a stem, 7i. having a flange, 7c, secured by a collar, 'lr/7,. upon the valve k, so as to permit the said stem to rotate indepeudently ofthe valve While moving the said valve longitudinally. The valve 7# is provided with lugs la, resting onguide-ribs 75m, (see Fig. 3,) on the interior of the case la, which thus relieve the stein 75 from lateral strain, and also prevent rotary movement of the valve relative to its seat, so that it always engages its seat in the same relative position and without sliding or rubbing action.

The main shell or casting 7u is provided with a stuffing-box, 7J, through which the valvestem l passes, the portion of the said stem outside the stuffing-box being screw-threaded, as shown, and operating in a nut or threaded yoke, k, connected with the main casting by rods r, so that the rotation of the valve-stem by a suitable hand-wheel, 7:, causes the said stem to inovelongitudinally, withdrawing the valve 7a" from its seat or moving it up thereto, as may be desired.

ln order toinsure that the discharge-opening may be tightly closed by the valve, so that no liquid can escape therefrom While the pulp material is being treated in the digester, the said valve is provided with a packing-ring, m, of lead or equivalent soft non-corrosive material embeddedl in the face' oi' the valve,

IOO

0communicates through the interior of the said and provided, as shown, with locking proice- I tions m', to securely fasten it to the said valve, the said ring being pressed in the seating of the valve upon the ridge Zi", which embeds itself therein, as shown, making an extremely tight joint.

The ring 'in is made by running the molten meta-l into a groove made to receive it in the face of the valve, the said groove being undercut to produce the locking projections m in the ring.

The case 7:. of the valve is provided with an outlet, k1, which, when the valve 76 is opened,

case with the discharge-opening t from the digester, permitting the digested material to escape from the tank t into any suitable receptaele, and the said valve-easing is provided at its upper side with a removable cap or bonnet, k, held in place by a yoke, k", and bolts Irl", the said yoke entering slotted studs kl, from which it can be removed by loosening l without wholly removing the bolts 7.1, thus enabling the said bonnet to be easily removed when it is desired to obtain access to the interior of the valve-casing for any purpose.

The opening in the case covered by thebonnet '/izIIL is large enough to permit the valve L to pass through it, and consequently, `it the packing is injured or is destroyed, so that the valve leaks, the said valve may be disconnected from the stem by simply unbolting the collar kl, after which it may be removed from the case and provided with a new packing-ring, or otherwise repaired.

I claim l. The combination, with a digestei provided with a discharge-opening for pulp material, of a valve controlling the said opening, and a packing-ring oflead or equivalent yielding non-corrosive material, and a ridge or raised portion (3o-operating with the said packing-ring, substantially as described.

2. The dischargepassage for a paper-di gester, combined with a valve and actuating-stem therefor, and a raised valve-seat, the saidl valve being provided with a packing-ring of lead embedded in its face and provided with locking projections securing it to the said valve, substantially as described.

3. The combination, withl a paper-digester having a discharge-passage, of a valve apparatus controlling the said passa-ge, composed of a case provided with a valve-seat and guides, a` valve co-operating with the said seat and guided by the said guides, and a valve-stein by which the said valve is operated, substantially as described.

4. The combination, with a paper-digester having a discharge-passage, of a valve apparatus controlling the said passage, composed of a case provided with a valve-seat, and a co-operating valve and valve-stem detachably connected therewith, the said case being provided with a removable bonnet of sufficient size to'permit the removal of' the valve when detached from itsstem, substantially as described.

5. The combination, with a paper-digester having a discharge-passage, of a valve apparatus controlling the said passage, composed of a case provided with a valve-seat and guides, a valve co-operating with the said seat and guided by the said guides, a packing-ring, and a valve-stein detachably connected With the said valve, the said case being provided with a removable bonnet'of sufficient size to permit the removal of the valve when detachedv from its stein, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EUGENE H. CL A PP.

Vitnesses:

Jos. l). LIVERMORE, W. H. SIGsrroN. 

